Answer:
x^2 + px + q = 0
x = - p/2 ± √((p/2)^2 - q)
x^2 - 4x + 3 = 0
x = - (-4)/2 ± √(((-4)/2)^2 - 3)
x = 2 ± 1
x1 = 1
x2 = 3
